Definition and Overview

An obstructed internal hernia is a medical condition wherein an internal organ protrudes through the peritoneum (a serous membrane that covers the abdominal organs) or mesentery but remains within the abdominal cavity. Internal hernias, which cause an intestinal obstruction, are not as common as other types of hernias, such as hernia of the stomach or the groin, more commonly known as inguinal and hiatal hernias, respectively.

While other types of hernias cause an outward protrusion, internal hernias protrude inwards. They occur internally, hence, they are harder to detect and identify, even when patients are already experiencing symptoms. In fact, some patients may have an internal hernia for several years without getting diagnosed. This condition is also often under-diagnosed or misdiagnosed as endometriosis or chronic pelvic pain. Because of this, internal hernias tend to be more dangerous as they can cause bowel obstruction and other complications, which can become quite serious by the time the hernia is diagnosed.

Internal hernias occur in different forms. The most common is paraduodenal hernia, which can occur in the left or the right part of the abdomen as a result of an error in the rotation of the midgut. Paraduodenal hernias account for half of all internal hernias. Other less common types include:

  • Transmesenteric hernia, up to 35% of which occurs among paediatric patients due to congenital defects

  • Transomental hernia, which accounts for 1 to 4% of all internal hernias

  • Pericecal hernia, which accounts for 13% of all internal hernias

  • Sigmoid mesocolon hernia

  • Supravesical and pelvic hernias

Causes of Condition

The factors that cause an internal hernia are different from the common causes of other types of hernias. While others are usually caused by heavy lifting, persistent coughing or sneezing, weakened stomach muscles, and strenuous activities, internal hernias could develop due to:

  • Congenital defect in the peritoneum or mesentery

  • Congenital intestinal rotation

  • Traumatic injury to the mesentery

  • Complication of a previous abdominal surgery, such as liver transplantation or gastric bypass surgery

  • Infective disease

Internal hernias that develop as a complication of abdominal surgery are most common following surgery to treat obesity.

Other common types of hernias include:

  • Incisional, a hernia that results from an incision

  • Umbilical, a hernia affecting the belly button

  • Groin hernia, such as an inguinal hernia, which occurs in the inner groin

  • Stomach hernia, such as a hiatal hernia, which develops in the upper stomach

  • Femoral hernia, in which the intestine enters the canal that carries the femoral artery all the way into the upper thigh

Of all these, internal hernias are the most serious. Nevertheless, all hernias need to be treated as soon as possible to prevent serious consequences.

Key Symptoms

Obstructed internal hernias can cause the following symptoms:

  • Chronic constipation

  • Hernia pain, which can either be epigastric or abdominal

  • Abdominal tenderness

  • Abnormal bowel sounds

  • Nausea

  • Vomiting

  • Palpation of a mass

  • Abdominal distension

  • Inability to eliminate flatus (gas in or from the stomach or intestines)

Internal hernias in women are quite challenging to diagnose than those in men. This is because when a woman lies down on an examination table, hernia symptoms tend to disappear. Thus, proper positioning of the body is required in order to provoke the symptoms and avoid misdiagnosing the condition.

Also, the signs of a hernia may sometimes be mild and intermittent, so many patients do not seek medical attention right away.

An x-ray and a computerised tomography (CT) scan often become necessary to check if there is an intestinal obstruction. Sometimes, exploratory laparotomy or laparoscopy may also be necessary.

Internal abdominal hernias account for 0.2 to 0.9% of all cases of bowel obstructions. If an obstruction is indeed present, an internal hernia can be fatal, as there is a high risk of strangulation. The loop of an internal organ that passes through the peritoneum or mesentery also becomes at risk of incarceration.

Who to See and Types of Treatments Available

Patients who are experiencing any unusual abdominal symptoms should see a general physician, primary care doctor, or internal medicine specialist who can make an initial diagnosis or order other tests if necessary.

The timely treatment of an obstructed internal hernia can prevent fatal consequences, and early diagnosis and careful examination of the signs of a hernia, in spite of challenges, is key. Also, aside from treating the hernia itself, the obstruction of the bowel should also be managed.

Patients suffering from an internal hernia with small bowel obstruction are initially treated using conservative methods, such as balancing fluid and electrolyte in the body and draining intestinal fluid to reduce hernia contents using a long intestinal tube (nasogastric tube decompression).

These treatments usually need to be followed by a midline laparotomy depending on the status of the bowel. In fact, the only effective and lasting way to treat a hernia is to have it repaired surgically.

In the event that an obstructed internal hernia leads to the development of gangrenous bowel, the gangrenous part has to be resected.

In some cases, patients have to undergo emergency surgery for hernia. Whether or not this is the case, patients who undergo laparotomy for hernia repair may need to stay in the hospital for several days up to a week. Sutures can be removed after two weeks.

For less severe cases, the condition can be repaired laparoscopically. This means that a big incision is no longer necessary. The doctor will simply repair the hernia using small surgical instruments passed through tiny incisions. This technique is safer and has a lower risk of complications. It minimises bleeding, blood loss, and recovery period.


  • Crispin-Trebejo B, Robles-Cuadros MC, Orendo-Velasquez E, Andrade FP. “Internal abdominal hernia: Intestinal obstruction due to trans-mesenteric hernia containing transverse colon.” Int J Surg Case Rep. 2014; 5(7): 396-398. Published online 2014 Apr 24. doi: 10.1016/j.ijscr.2014.01.013

  • Rambhia SU, Madhukar P. “Internal hernia – a rare cause of small bowel obstruction: a case report.” International Surgery Journal. Rambhia SU et al. IntSurg J. 2017 Jan; 4(1): 427-428.

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